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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRLX 231857
AFDRLX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON WV
257 PM EDT THU MAY 23 2013

.SYNOPSIS...
-- Changed Discussion --
SECOND COLD FRONT CROSSES THIS EVENING. UPPER DISTURBANCE CROSSES
EARLY FRIDAY MORNING. COOL CANADIAN HIGH PRESSURE ARRIVES TO START
THE WEEKEND.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH FRIDAY/...
-- Changed Discussion --
SHRA/TSRA ALONG A LLVL CONVERGENCE BOUNDARY IN C WV...WHICH WILL
SHIFT E NEXT SEVERAL HRS. HAVE LKLY POPS WITH THIS AS IT WORKS
INTO REMAINDER OF CWA LATER THIS AFTN. MAY SEE SOME MTN SHRA FORM
AHEAD OF THIS ON DIFFERENTIAL HEATING. SHOULD SEE SOME DEEPER
CONVECTION FORM SHORTLY WITH SOME SFC HEATING. LATEST SPC MESO
DISCUSSION HAS PLACED MUCH OF WV ZONES IN POTENTIAL FOR WATCH. NOT
SURE HOW STRONG CONVECTION WILL BE WITH LESS SFC INSTABILITY THAN
PAST FEW DAYS. HOWEVER...FRZ LVLS ARE LWR AND BETTER UPR SUPPORT
WITH APPROACH OF UPR TROF. DEEPER SHEAR A LITTLE BETTER THAN
YESTERDAY AS WELL. DAMAGING WIND PROGS NOT AS IMPRESSIVE AS PAST
FEW DAYS WITH MDLS SHOWING MARGINAL DOWNDRAFT SIGNAL AS SFC TO H7
DELTA THETA E NOT AT GREAT. OF PERHAPS MORE CONCERN IS WATER.
CONCERNED S PART OF THIS BOUNDARY MAY TRY TO TRAIN SOMEWHAT WITH
THE BETTER PUSH ACROSS SE OH/N LOWLANDS INITIALLY. ALREADY SEEING
THIS HAPPENING NEAR TRI STATE. 1 HR FFG HAS COME DOWN CONSIDERABLY
WITH MUCH OF WV ZONES 1 TO 1.25 INCHES AND N LOWLANDS LESS GETTING
DOWN TO .75. ISSUED FLASH FLOOD WATCH EARLIER FOR MUCH OF THE
LOWLANDS AND N MTNS. WILL END IT AT 00Z WITH PWS COMING DOWN TO 1
INCH.

MAY SEE A FEW BANDS OF SCT SHRA/TSRA BEHIND THIS UNTIL UPR TROF AXIS
AND COLD FRONT CROSSES THIS EVE. SHOULD SEE SOME POST FRONTAL
SHRA CONT ALONG AND E OF I79 OVERNIGHT WITH LOW STRATUS DEVELOPING
ELSEWHERE.

CAA COMMENCES IN EARNIST LATE WITH H85 TMPS BOTTOMING OUT CLOSE TO
0Z. NOT OUT OF THE QUESTION FOR SNOWSHOE TO SEE SOME WET
SNOWFLAKES ARND DAWN. AS TROF AXIS PULLS E COLUMN COLUMN DRIES OUT
CONSIDERABLY AND WILL ALLOW MORNING STRATUS TO MIX OUT IN MORNING
WITH JUST SOME FLAT CU IN AFTN HEATING. WENT CLOSER TO MET FOR
HIGHS WITH LWR 60S AND SOME 40S IN HIGHEST ELEVATIONS...DEFINATELY
NOT INDICATIVE OF LATE MAY.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
DRIER...COOLER WEATHER TO SET UP ACROSS THE REGION BEHIND THE
EXITING UPPER TROUGH. 850MB TEMPS WILL DROP INTO THE SINGLE DIGITS
FRIDAY NIGHT...SOME OF THE COOLEST AIR WE HAVE SEEN IN A FEW WEEKS.
THIS...ALONG WITH HIGH PRESSURE SETTLING INTO THE REGION...AND A
CLEARING SKY...WILL SEE GOOD RADIATIONAL COOLING FRIDAY NIGHT...AND
FROST/FREEZE HEADLINES MAY BE NEEDED IN MANY
LOCATIONS...PARTICULARLY ACROSS THE NORTH. IN MOUNTAINOUS
COUNTIES...THIS WOULD MAINLY AFFECT SHELTERED VALLEYS...AS NOCTURNAL
LLJ SHOULD PREVENT FROST FORMATION. WILL HIGHLIGHT THE POTENTIAL FOR
FROST/FREEZE IN THE HWO. FLY IN THE OINTMENT HOWEVER WILL BE THE
POTENTIAL FOR MID AND HIGH CLOUDS MOVING INTO THE AREA FROM AN UPPER
DISTURBANCE. THIS MAY PREVENT FROST FORMATION PARTICULARLY ACROSS
EASTERN KY...SOUTHWEST VA...AND SOUTHERN COAL FIELDS OF WV.

COULD SEE A SLIGHT CHANCE FOR SHOWERS SUNDAY MORNING ACROSS SOUTHERN
ZONES...BUT FOR NOW...MUCH OF THE ENERGY AND MOISTURE ASSOCIATED
WITH THIS LOOKS TO REMAIN OFF TO OUR WEST...SO FOR NOW WILL MAINTAIN
A DRY FORECAST SUNDAY MORNING.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
HAVE GENERALLY FOLLOWED WPC THINKING FOR THIS PORTION OF THE
FORECAST.

HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER ACROSS THE AREA INTO
SUNDAY NIGHT.  HOWEVER...MODELS SUGGEST A FEW WEAK MID-LEVEL
SHORTWAVE MAY MOVE SOUTHEAST.  BELIEVE AREA SHOULD REMAIN DRY...WITH
A FEW MORE CLOUDS BEGINNING SATURDAY NIGHT

A WARM FRONT WILL THEN DEVELOP AND APPROACH THE REGION ON MONDAY. AS
A RESULT...THERE WILL BE A CHANCE OF SHOWERS AND STORMS MONDAY AND
TUESDAY...MAINLY DURING THE AFTERNOON AND EVENING HOURS.

TEMPERATURES ON SATURDAY SHOULD BE NEAR NORMAL WITH DAYTIME HIGHS IN
THE 70S ACROSS THE LOWLANDS...WITH 60S ACROSS THE HIGHER
ELEVATIONS.  AS THE HIGH PUSHES EAST ON SUNDAY...EXPECT TEMPERATURES
TO WARM TO SLIGHTLY ABOVE NORMAL VALUES MONDAY AND TUESDAY.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
LLVL CONVERGENCE BOUNDARY SERVING AS FOCUS FOR SHRA/TSRA THIS AFTN
WHICH WILL SHIFT GREATEAST COVERAGE INTO MTNS BY 21Z...BRINGING MVFR AND
LOCALIZED IFR CONDITIONS...AND POSSIBLY GUSTY WINDS. HAVE SOME
TEMPO GROUPS TO TRY AND COVER WITH VCSH AND VCTS IN THE
PREDOMINATE GROUP. MAY SEE ANOTHER BAND OF SHRA AND ISO THUNDER
WITH ARRIVAL OF UPR TROF AND COLD FRONT AFTER 00Z.

EXPECT SOME POST FRONTAL SHRA TO LINGER OVERNIGHT...MAINLY IN
MTNS. MVFR STRATUS TO DEVELOP AS WELL AT ALL TAF SITES WITH
PERHAPS SOME IFR BASES IN MTNS. THIS WILL SCT OUT FROM W TO E IN
THE MORNING WITH JUST SOME SCT FLAT CU FOR AFTN.

W FLOW AND A BIT GUSTY THIS AFTERNOON...AS A SURFACE TROUGH MOVES
THROUGH...AND THEN W TO NW AND GUSTY TONIGHT...AS A COLD FRONT
MOVES THROUGH. LIGHT SW FLOW ALOFT THIS WILL BECOME W LATE
TODAY...AND THEN MODERATE NW OVERNIGHT TONIGHT.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...

FORECAST CONFIDENCE...MEDIUM TO HIGH.

ALTERNATE SCENARIOS: FORMATION...TIMING AND DEGREE OF FLIGHT
RESTRICTIONS DUE TO CONVECTION THIS AFTERNOON INTO THIS EVENING
COULD VARY. TIMING AND EXTENT OF MVFR /OR LOWER/ STRATOCU FORMING
LATER TONIGHT COULD ALSO VARY.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       18   19   20   21   22   23   00   01   02   03   04   05
EDT 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
CRW CONSISTENCY  H    M    H    H    H    M    M    M    M    H    H    M
HTS CONSISTENCY  M    H    H    H    M    M    M    M    M    H    H    H
BKW CONSISTENCY  H    H    H    M    H    H    M    M    M    M    H    L
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    L    L
PKB CONSISTENCY  H    H    H    H    H    M    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    M    H    H    M    M    M

AFTER 18Z FRIDAY...
IFR CONDITIONS POSSIBLE IN FOG EARLY SATURDAY MORNING.
-- End Changed Discussion --

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR WVZ008>011-
     013>020-025>032-038>040-046-047.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...ARJ/30
NEAR TERM...30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...30/TRM